Hydrochloric Acid → 6-fluoro-4-oxo-3,4-dihydro-2H-1-benzopyran-2-carboxylic acid

HRID 1723358Notes

Reaction equation

HRID 1723358 reaction equation
C(=O)(O)[O-].[Na+].[F:6][C:7]1[CH:8]=[CH:9][C:10]([OH:20])=[C:11]([C:13](=[O:19])/[CH:14]=[CH:15]/[C:16]([OH:18])=[O:17])[CH:12]=1.Cl>O>[F:6][C:7]1[CH:8]=[CH:9][C:10]2[O:20][CH:15]([C:16]([OH:18])=[O:17])[CH2:14][C:13](=[O:19])[C:11]=2[CH:12]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 516892Sodium BicarbonateHCID 145552584-(5-Fluoro-2-hydroxyphenyl)-4-oxobut-2-enoic acid

Product 1

HCID 27785256-fluoro-4-oxo-3,4-dihydro-2H-1-benzopyran-2-carboxylic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Sodium bicarbonate (2.10 g, 25.0 mmol) was added to a suspension of (E)-4-(5-fluoro-2-hydroxyphenyl)-4-oxo-2-butenoic acid (5.00 g, 23.8 mmol) (obtained through the process as described in Example 22) in 200 ml of distilled water and the mixture was refluxed for 10 minutes. After cooling, the reaction mixture was acidified to pH 1.0 with concentrated hydrochloric acid and then extracted with ethyl acetate. The organic layer was dried over anhydrous sodium sulfate and evaporated in vacuo to give crude crystals which were recrystallized from the mixture of water and methanol to give 4.60 g (92.1%) of the subject desired compound as colorless crystals.

Workup

  1. customobtained through the process
  2. temperaturethe mixture was refluxed for 10 minutes
  3. temperatureAfter cooling
  4. extractionextracted with ethyl acetate
  5. dry with materialThe organic layer was dried over anhydrous sodium sulfate
  6. customevaporated in vacuo
  7. customto give crude crystals which
  8. customwere recrystallized from the mixture of water and methanol
  9. customto give 4.60 g (92.1%) of the

Sources & evidence

ORD record
ord-d49ff0bfc386456ebc48882524f31209
Source dataset
uspto-grants-1989_08
Patent number
US04861792

Reaction notes

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